Ingestible devices that include electronic circuitry have been proposed for use in a variety of different medical applications, including both diagnostic and therapeutic applications.
Examples of such ingestible devices are ingestible electronic capsules which collect data as they pass through the body, and transmit the data to an external receiver system. An example of this type of electronic capsule is disclosed in U.S. Pat. No. 5,604,531 Iddan et al., which describes what is called an in vivo video camera. The swallowable capsule includes a camera system and an optical system for imaging an area of interest onto the camera system. The transmitter transmits the video output of the camera system and the reception system receives the transmitted video output. U.S. Pat. No. 7,009,634 also issued to Iddan et al discloses an ingestible imaging device that obtains images from within body lumens or cavities. The electronic circuit components of the device are enclosed by an inert indigestible housing (e.g. glass housing) that passes through the body internally. U.S. Pat. No. 6,800,060 issued to Marshall discloses an ingestible data recorder capsule medical device. The electronic circuits of the disclosed device (e.g. sensor, recorder, etc.) are housed in a capsule made of inert materials, and therefore ingestible and passable through the digestive tract without being consumed by the body.
In these devices, the electronic circuits are protected in a housing or capsule that prevents damage to the device's electronic circuits during the process of ingestion and elimination in the human body.
Recently, U.S. Patent Application Publication No. 2007/0008113 by Spoonhauer et al. disclosed fragile radio frequency identification (RFID) tags for use in drug ingestion monitoring applications. The RFID tags disclosed in this application are simple antenna structures that are configured to break down during transit through the body.
In certain instances, more complex circuitry suitable for use in ingestible devices is needed.